Hoist



R. J. WADD 2,053,055

HoIsT Filed Aug. l, 1954 4 Sheets-Sheet 1 @T1 m. mf N w f m 4 m Y Nm. .E n mw v w wr. .www A m wm NN m %v/ 4 @w A W .H MI n m. `ll\\\ M A mw W. WN h H Iwwwww M i L o o o, QN n `1X Mm mw, Q/ S wmf l ---maw L@ o lil w o o m mw O \%\\HHMI- .MW QN mm, NR n\. N u lnllm M mw, l n M. mw \||IJ mh. WWF/awa n N NN Q N C @Q WT m "mi" (ANW `w W Sept. 1, 1936.

v 71 ATTORNEY sepa. 1, 1936. Y Q J, WADD 2,053,055

HOIST Filed Aug. lI 1934 4 Sheets-Sheet 3 l* 1111/', 1 T y Y j "EN H l a INVENTOR.

4/75 Us l )7 ATOW Sept. 1, 1935. l R. J. WADD 2,053,055

HOST

Filed Aug. l, 1934 A 4 Sheets-SheetA INVENT( "H.

ATTORNEY! Patented Sept. i, 191356 HORST Application august Liss/i, sei-iai No. 737,92@ 9 claims. (ci. 25u-16s) This invention relates in 'general to hoists'and more particularly to electricv hoists of the type wherein the hoisting mechanism or hoisting drum, the driving motor and the gearing between the driving motor and the drum, as well as the braking mechanism employed, are all compactly organized in a single unitary structure. In fact,

with hoists of thistype it is important that the assembly be as compact as practical in order to 10 use the hoist in crowded quarters as well as for other reasons. Heretofore, one of the deciencies y of this type of hoist has been the lack of exibility of the gearing'employed in respect of variations in speed and power ratios. With the. prior l5 constructions a maximum ratio range has not been available in a compact unit which adequately meets the requirements of industry and certainly this is particularly true in any construc-` tion which is adaptable to the other requirements 2o of hoists of this character and which operates with emciency. q

One of the objects of the present invention is to provide a. hoisting mechanism so constructed and organized as to render available a wide range of gear ratios and to vaccomplish this while rendering the structure even more compact and more etiicient. Combined with these advantageous features is a novel load brake which precludes the load overrunning the motor when lowering while avoiding any lateral sliding action in the operating gears, thus aording a free braking action directly in proportion to the applied load.

Another object of the invention is to provide a hoist having these advantages and capacities and which has incorporated in its structurean advantageous form of stopping brake which is capable of functioning as a holdingbrake in instances where the automatic load brake is not used.

40 Still another object of the invention is to pro- .vide a hoist mechanism of this character which is simple and durable in its construction, reliable and emcient in its operation, and easy and comparatively inexpensive to manufacture and main- 15 tain." n

A further object of the invention is to provide a hoist of this character which is so constituted as to provide an enclosure for the gearing and the load brake mechanism so that the gearing may be immersed in a bath of lubricant.

Another object is to provide a hoist havin these advantages and which embodies in its constructionV a novel means for limiting the approach of the load block to the winding drum, such means providing for the automatic movement of the motor controlling switch iirst to ofF position and in the event of continued drift or approach of' the load block to the hoisting drum, then reversal of the driving motor for e. short period, whereupon the switch returns to oi position.

Other objects and advantages reside in certain novel features of the construction, arrangement and combination of parts which will be hereinafter more fully described, and particularly pointed out in the appended claims, reference being had to the accompanying drawings, forming a part of this specificatidn, and in which:

Figure l is a View partly in elevation and partly in central vertical longitudinal section showing a hoist constructed in accordance with the 15 present invention, parts being broken away for the sake of illustration;

Figure la is a fragmentary view in vertical section but taken on the plane of line a-a of Figure d; 20

Figure 2 is a view in transverse vertical section taken on line 2 2 of Figure 1, and also showing in addition one type of suspension of the hoist, the load block and one manner of suspending the same and an automatic limit switch arrange- 25 ment;

Figures 3, 4 and 5 are views in transverse vertical section taken on lines 3 3, and 5 5, respectively, of Figure 1, Figure 5 being on .a somewhat smaller scale; 30

Figure 6 is a fragmentary View in elevation illustrating one set of camming lugs employed for applying braking pressure between the braking members of the automatic load brake;

Figure 7 is a fragmentary view in section taken 35 Y on line 'E 'i oi Figure 2;

Figure 8 is a view in vertical section taken on line 8 3 of Figure 2 Figure 9 is a fragmentary sectional view taken on line 9 9 of Figure 2; and

Figure l0 is a fragmentary view in central vertical longitudinal section illustrating a. modification of the hoisting drum to provide for a multpie reeving of the hoist line.

Referring to the drawings, and more particularly to Figures 1 and 2, it will be seen that the hoist embodying the present invention comprises generally a main frame member i suspended by means of a trolley 2 from a monorail 3. However, y 'the invention is adaptable to any suitable suspen- 50 sion means, as, for instance, a hook suspension, a motor driven or other trolley suspension, or any of the various types of xed suspensions or supports. Within the main frame member a hoistn ing drum, is supported for rotation. 0n one "5 -drum4.

end of the main frame member I an electric motor 5 is securely mounted. 0n theopposite end thereof a gear casing 6 is secured and houses the gearing designated generally at 1 which serves to .transmit the 4drive from the motor 5tol the hoist An automatic load brake designated generally at 8 is also. provided within the gear casing 6. A housing 9 is securely fastened to the outboard end of the gear casing 6 and encloses a holding brake designated generally at I0. A load block I.I (see Figure 2) having a hoisting hook I2 is suspended from the lhoisting drum 4 by means of a hoisting line I3, one end of which may be l anchored or dead-ended as at I5 and the other end portion of which is secured to and coiled about the hoisting drum 4.

A switch box I6 is fastened to a bracket I1 carried in the main frame and contains a switch I8 which controls the supply of current to the motor 5. 'Ihe switch I8 is normally operated from a control lever I9,`the ends of which are equipped with pull cords I9', which the operator manipulates, but in the event the load block II approaches too close to the hoist drum 4, the switch I8 is properly manipulated automatically from a stop lever 20 actuated by the load blockl I.

As shown in Figure 1, the electric motor 5 has one end of its casing 2I fitted in a flanged seat 22 provided on one end wall 23 of the main frame i and is securely` bolted or fastened in position against such seat in any suitable manner. The armature shaft 24 of the motor 5 is connected to a drive shaft 26 by means of a coupling sleeve 21, the coupling sleeve 21 being splined or keyed to thearmature and drive shafts. A roller bearing assembly v28 suitably fitted and secured in the `end wall 23 of the main frame supportslthe coupling sleeve 21 for rotation. Y

The gearing 1 may b e characterized broadly as a planetary gear set'of the differential epicyclic type and comprises a driving pinion30, `the teeth of which are formed on one end of a sleeve-like hub 3i splined to the drive shaft 26, as illustrated in Figures 1, la and 4. A plurality ofsets of planet pinions designated generally at 32 is provided, each set of planet pinions being double,

. that is, consisting of two pinions, one designated at 33 and the other at 34, the pinions 33 and 34 of each set being integral or else otherwise rigidly fastened together. Each set of pinions is` rotatably supported on a pinion shaft 35, the shafts 35 having their ends mounted in the plates 36 and 31 of a carrier designated generally at C. .'I'he construction of the vcarrier is completed by arcuate webs 31' (see Figure 3) which connect portions of the peripheral edges of the plates 36 and 31 and may be integral with said plates or else welded or otherwise fixed thereto. If desirable, suitable roller bearings, such as are designated at 35', may be provided between each set of pinionsand their pinion shafts and washers or wear plates 36 may be provided between the side faces of the pinions and the carrier plates. The carrier plates are mounted for rotation in a manner which will be hereinafter pointed out. The pinions 33 -mesh with an internal gear ring 38 fitted in a shouldered seat 39 provided therefor in the gear casing and although free for a limitedrotary movement the ring gear 38 is efectually fixed or stationary in the operation of the hoist.l

ing in the ball bearing assembly 43 and being -indirectly supported for rotation in the ball bearing assembly 44 due to the interpositioning between the bushing and such bearing 44 of the hub ange of the second internal 'ring gear 40. This flange 49' of the ring gear 40 is firmly secured or keyed to the bushing 4I and since the bushing 4I is keyed as at 42 to the hub of the hoist drum 4, the motion of the internal ring gear 46 is transmitted directly to the hoist drum. It will be noted that the inner end of the bushing 4I projects beyond the body of the ring gear 40 and braking elements or ldiscs and 46 disposed on the opposed sides of an interposed braking element or disc 41, the latter being provided with facings or brake lining 41 on the surfaces that are engaged by the braking discs 45 and 46. The braking disc 45 has its flanged periphery engaged on a shouldered seat 41 provided therefor on the gear casing 6 and it is fixed in position by means of a key 41h. Its cooperable braking disc 46 is, however, supported for rotary and slight axial movement in the housing as will hereinafter more clearly appear.

The braking disc 41 is connected to the carrier plate 31 by means of a one-way clutch or ratchet device so that the load brake Will be operative only when lowering and when the hoist is stationary, the one-wayz clutch automatically disconnecting or freeing the hoist of the action of the load brake when hoisting. As shown in Figures l and 4, the one-way clutch 48 comprises an outer clutch member 49 rotatably fitted on an inner collar-like clutch member 5U fastened by means of screws 5I to the carrier plate 31 of the gear set. 'I'he inner clutch member 50 is supported -for rotation von 'a hub-like annular flange 58 which is preferably an integral extension 0f the end wall 59 of the housing 9. At angularly spaced points in the periphery of the inner clutch member 50, notches 52 are machined and these 'notches have the bottoms or floors thereof inclined as shown in Figure 4. Rollers 53 are positioned in the notches 52 and are urged outwardly into engagement with the inner periphery of the outer clutch member 49 by means of spring pressed followers 54. With a construction of this character, when the carrier plate 31 of the planetary gear set rotates the inner clutch member 50 in a clockwise direction, as viewed in Figure 4, and with the outer clutch member 49 retarded under the action of the brake discs 45, 46 and 41, the rollers 53 will drift down into the deeper portionsV of the notches 52 and there will be no eiective connection between the clutch members 49 and 50. On reverse rotation ofthe inner clutch member 50,

that is, rotation thereof in a counter-clockwise direction and with the rotation of the clutch member 49 restrained,.the rollers 53 will be accepte brought into wedging engagement between the inclined oors of their notches 52 and the inner periphery of the outer clutch member 69 so that these clutch members will be eifectually connected vtogether with the consequence that the planetary gear set will operate against the resistance of the braking discs t5, 46 and 41.

For the purpose of varying the braking pressure of the discs 435 and B6 on the interposed braking disc 61,'motion is taken from the internal ring gear 38. and is transmitted through the braking disc 136 to bring into action a plurality of cooperable cams or helical surfaces, designated at et and et, the cams 55 being provided on one face ofthe braking disc it and the camsv @t on a stationary disc l fastened to the end wall 59 of the housing 9. As shown in Figures l, 3 and fi, the ring gear 38 has projecting from ,one side thereof at angularly spaced points integral arms S9, the arms extending through arcuate slots ti and 62 formed in the periphery of the Ydiscs i5 and 56, respectively, and being located beyond the periphery of the braking disc fil. As will be understood from the drawings, the discs 35 and B6 have their peripheries flanged to strengthen them. These flanges, however, are cut away at the points where the slots ci and 't2 are formed. The slots in the periphery of the brake disc i5 are suiilciently large to allowv gear set 32, and the pinions 33 thereof will rst cause the ring gear 38 to rotate. Such rotation of the ring gear will be transmitted through the arms 60 to the brake disc 56. When this rotation is in such direction as to cause the cammin'g lugs 55 to move to the left as viewed in Figure 6, their inclined surfaces will ride along the inclined surfaces of the camming lugs 56 and force the clutch disc 66 to the left as viewed in Figure lythereby causing it to press with greater "force against the clutch disc 41 and the latter .in turn to press harder against the-clutch disc t5. As a consequence, the rotation of the clutch disc @l is more rmly retarded and the braking effect exerted is directly 'in accordance with the load applied to the hoist.

. The stopping brake i0 is preferably of the disc type and of I a 'character which is biased to braking position by a.- spring or the like and released by means of an electromagnet so connected up in the motor circuit as to be automatically energized whenever current is supplied to the motor. Thus, as illustrated, the stopping brake consists of a pair of brake discs 65 and S6, brake disc 65 being stationary and abutting against one side of the end wall 59 of the housing 9, whereas the brake disc S6 is movable and is supported for shifting movement on supporting elements; or bolts 6l. interposed between the discs 65 and .66 is a brake disc Bhaving brake lining or surfacing i0 on the faces thereof with which the brake discs 65 and 66 are engageable. The inner periphery of the brake disc 68 is toothed to intert with a toothed or ribbed formation 66 provided on the adjacent end of the sleeve-like hub 3i of the driving pinion 3D of the gear set. It will be noted that this sleeve-like hub 3l intermediate the pinion'30 and the toothed or ribbed formation 66 is rotatable in a bushed bearing 6l' provided therefor in the annular flange 58 of the end wall 59 of the housing 9.

An operating lever 1I is provided for the stop- S6. The end' of the lever 'H opposite its fulcrum' is engaged by a plunger which slides in a sleevelike bracket 'i5 provided therefor and which is urged against the lever by a coil spring 16. The rod 'il of the plunger projects beyond the bracket 'i5 and has a collar 18 fixed thereto which is piv= otally or otherwise appropriately connected as at 'i9 to the armature 80 of an electromagnet 8l.

It is obvious that spring 'i6 applies the stopping brake and that electromagnet 8l, when energized, releases it. It is conventional to have such a magnet so connected in the motor circuit that it is automatically engaged when the motor is running and disengaged when the motor stops. i

The switch which controls the energization of the motor 5 is illustrated in Figures 2, 8, and 9,

and, as shown, comprises xed contact segments 85 and 86 made up of a sufficient number of singularly spaced metal contacts 81 separated by .insulation 88 to provide for the rotation of the motor in one direction or the other to take care of hoisting and lowering. A movable contact arm 89 is mounted to sweep back and forth across the Contact segments 85 and 86 and has bridging contacts 9U and 9i which,iin one position, bridge the contacts 37 which run the motor forward, in another position bridge the contacts which reverse the motor 5 and in the third position, that shown in Figure 8, break the motor circuit. The details of the switch per se form no part of the invention and hence will not be further described. Such switches are well known to those skilled in the art.

The hub 92 of the contact arm 89 is rotatably .mounted on a supporting shaft 93 which is, in turn, mounted for rotation in bearings provided therefor in the switch box I6. In order to bias the switch arm 89 to the position shown in Figure 8, in which position the motorv circuit is broken, a spring 94 is coiled about the hub 92 and has its ends 95 extending vertically and embracing ory straddling pins 96 and S1, the pin 98 being fixed to the structure of the gear box and projecting forwardly between the terminals 95 of the spring, whereas the pin 91 is fixed to the hub 92 of the movable switch arm and projects rearwardly between the spring ends 95. It will be understood from this that the movable switch arm 89, when moved either to the right or to the left from the position shown in Figure 8*, partakes of such movement against the action of the spring Sc so that the spring 94 is constantly exerting a force on the movable switch arm tending to return it to open position (see Figure 8) The central portion of the operating lever i9 is fixed to the shaft 93. Normally there is a mechanical connection between this shaft 93 and the 1 approach toward the hoisting drum the stop lever a laterally extending stud or pin |02 which ordinarily is seated in the notch and is releasably held therein by a blade spring |03 xed on the switch arm 89 and bearing down on the link 99.

The stop lever 20I has a bail-like portion |04 which lies in the path of movement of the load block I I, as will be understood from Figures Zand,

7. This bail-like portion is connected to a T- shaped portion |05, the latter being fulcrumed as at |06 on a bracket |01 carried by a switch box I6. The outer end of portion |05 is bifurcated as at |08 and straddles a nut-and washer assembly |09 carried by the lower end of 'a connecting rod IIO which extends into the switch box and is pivotally connected as at III to a crank arm I|2 pivbtally or rockably fitted on the shaft 93. Integral with the crank arm I I2 is a camming arm I I3, the camming arm II3 having a camming surface I|4 underlying the link 99 and cooperable with the adjacentk curved end of the link to lift the link and disengage its stud |02 from the notch I0| under certain conditions, as will be hereinafter more fully described'. The camming arm ||3 also has an integral extension l5 provided with a laterally extending stud IIE which'is, under certain circumstances, engageable with the shoulder-like formation II'I provided on ythe switch armfas will also be hereinafter fully pointed out.

When the operator desires to hoist or raise the load block he pulls downwardlyl on the left hand pull cord I9' (as viewed in Figure 8) to cause the bridging contacts `90 and 9| thereof to bridge such fxedcontacts 8l as to cause the motor -jacent curved end of the link 99 thereby lifting the pin |02 on the link 99 out of the notch IOI. The movable switch arm 89 is now free to rock on the s haft 93 undervthe influence of its spring 94 and it is at once returned to the position shown` in Figure 8, wherein the circuit 'to the motor'is broken. Should the block II continue to drift or 20 will be further rocked and consequently the camming arm 3 will be rocked still furtherv in a. clockwise direction so that Veventually its pin I I6 will engage the shoulder formation I I'I on the switch arm'89' to swing this switch arm from the position shown in Figure 8 in a clockwise direction, as viewed in such gure, until its contacts 9| bridge such of the xed contacts 01 as will bring about a reversal of the motor. When the motor `reverses' the load block is lowered and consequently the stop lever 20 under the influence of its own weight swings downwardly. This correspondingly moves the cam arm I3 and its pin I I Ii.v The movement of the cam arm- II 3 and pin I I6 is now in a counter-clockwise, direction, as viewed in Figure 8. The switch arm 89 under the influence of vits spring 94 follows the pin'- II Iil in such movement until the switch arm 'returns to its oi position. During this time the pin-|02 of the link able gear ratio.

99 has been riding on the curved surface ||8 of the sector-shaped arm- 98 and it will remain on some portion of this surface I I8 until the operator moves the lever I9 back to its horizontal position whereupon the pin |02 will snap into the notch |0| and the device will be reset.

In Figure 10 of the drawings there is shown a modified -type of drum and a slight modication in the structure of the'main frame member, all for the purpose o1 providing for a multiple reeving of the hoist line. As therein illustrated, 5 designates the motor and 26 the drive shaft, both of which may be constructed as previously described. 'I'he III as before, although its structure from the point of view of design is somewhat modified as will be understood from the drawings.

It will be understood from the foregoing that a hoist embodying the invention disclosed may be constructed to provide practically any desir- This flexibility in the gear train flows from the capacity of the differential epicyclic planetary gear set in its adaptability to provide in a practical way a. maximum gear ratio of range. y This variability or flexibility in the gear ratio range is had merely 'by varying the movement of teeth in the driving pinions,-the planet pinion and the ring gear. And this advantage'is had while enhancing the desirable feature of compactness. In other words, the overall dimensions' of the hoist embodying this invention occupies a minimum of space. In fact, a hoist desired to handle loads mato one ton occupies just about one-half the space as previous hoists'of thishtype; Furthermore, the eiliciency of the hoist'and its durability are enhanced and the cost oi.' producing the hoist and oi operating and maintaining it are materially reduced.

v Then again, the automatic mechanical load brake combined with the hoist provides a brakload, either when the holst is stationary or when lowering,"and yet when hoisting the mechanism is freed automatically of the restraining influence oi' the brake.

While I have shown and described typical embodiments 'ci' the invention, it isto be understood that the constructions shown have been selected merely for the purpose of illustration or example, and that various changes in the size, shape and arrangement of the parts may be made, as will be apparent to those skilled inl ithe art, without departing from the spirit of the invention or the scope of the subjoined claims.

'I'he invention claimed is: l

1. A hoist comprising a vrotatable hoisting drum, a driving motor therefor, and a planetary gear set providing a driving connection between said motor and said drum and comprising a driving pinion actuated by the motor, a plurality of pairs of planet pinions, a carrier for said planet pinions, one pinion of each of said pairs meshing with said driving pinion, two internal ring gears' "meshing with said planet pinions, means for constraining one of said ring gears to a' limited amount oi rotation and thereafter holding 1t against further rotary movement, and

ving effect directly in accordance with the applied l means for connecting the otherr of. said ring gears to said hoisting drum, the driving pinion, planet pinions and ring gears having an .unequal number of teeth so as to provide the desirable Vspeed and power ratio, in combinationiwith an automatic load brake having a. plurality of braking elements, one of which is connected to the carrier of said gear set and another of said braking elements being secured in ilxed position, cam- 4 ming means coacting with-still anotherof said braking elements for applying braking pressure therebetween, and means utilizing the limited rotation of the one of said ring lgears for actuating said camming means.

2. A hoist comprising a hoisting drum, a driving motor therefor, a gear set actuated by said motor and connected to` said drum to provide a driving connection for the motor and drum, and an automatic load brake for said hoisting drum vcomprising a braking disc connected to said gear set, a xed braking disc engageable with one face of said Erst-named disc, an axially shiftable disc engageable with the other face thereof, cooperable cams for shifting said last-nameddisc axially to apply said brake and means actuated by said gear set for actuating the cams.

3. A hoist comprising a hoisting drum, a driving motor therefor, a gear set actuated by said motor and connected to said drum to provide a driving connection between the motor and the drum, -said gear set having one ring gear constrained to a. limited amount oi rotarymovement, a gear casing enclosing said gear set, and an automatic load brake for said hoisting drum, also mounted in said gear casing and comprising a braking disc connected to said gear set, a

iixed braking disc engageable with one face of said Erst-named, disc, an axially shlftabl braking disc engageable with the other face thereof, cooperable camming means Abetween said lastnamed disc and said gear casing for shifting said last-named disc axially to apply said brake, and means actuated by said gear set for actuating the cams. l

4. A hoist comprising a hoisting drum, a driving motor therefor, a gear set actuated by said motor and connected to said drum to provide a driving connection between the motor and the drum, said gear set having one ring gear constrained to a limited amount of rotary movement, a gear casing enclosing said gearset, and an automatic load brake for said hoisting drum, also mounted in said gear casing and comprising a braking disc connected to said gear set, a xed br'aking disc engageable with one face of said rst-named disc, an axially shiftable braking disc engageable with the other face thereof, cooperable camming means between said last-named,

disc axially to apply said brake, and arms carried by said ring gear and engageable with said last-named disc for moving the same to cause the' cams to engage'and shift said last-named disc axially. Y

5. In combination with a hoist having a hoisting drum, a hoisting line actuated by the drum, a load block raised and lowered by said hoisting line, and an electric motor for driving said drum, of means for limiting the approach of the load block toward the hoisting drum and comprising a switch for controlling the supply of current to the motor and having a swingable switch arm and stationary contacts with which' said switch arm'is engageable, manually controllable means for swinging said arm including a lever and a releasable connection between accanto line, an electric 4motor for driving said drum, of

means for Hunting the approach of the load block toward the hoisting drum .and comprising a switch for controlling the supply of current to the motor and having a movable switch arm, means for biasing the switch arm to oil" position, manually controllable means for swinging the same arm to on position and including a lever and a releasable connection between the lever and said arm, and means for disconnecting said releasable connection including a stop lever adapted to be engaged by the load block and a trip for said releasable connection actuated by said stop lever when the latter is shifted by the load block.

'7. In combination with a holst having a hoisting drum, a hoisting line actuated by the drum. a load block raised and lowered by said hoisting line, an electric motor for driving said drum, of means vfor limiting the approach of the load block toward the hoisting drum and comprising a switch for controlling. the supply of current to the motor and having a movable switch arm,'

Vsaid releasable connection including a stop lever adapted to be engaged by the load block and a trip for said releasable connection actuated by said stop leverwhen the latter is shifted by the load block, said trip having means for engaging the arm and shifting the same to "reverse position upon continued drift of the load block toward the drum after said releasable connection has been disconnected.

8. In combination with a hoist having a hoisting drum, a hoisting line actuated bythe drum, a load block raised and lowered by said hoisting line, an electric motor for driving said drum, oi means for limiting the approach of the load 'block toward the hoisting drum and comprising a switch for controlling. the supply of current to the motor and having a movable switch arm, means for biasing the switch arm to "o position, manually controllable means for swinging the said arm to "on position and including a lever and a releasable connection between the lever and said arm, and means for disconnecting said releasable connection including a stop lever adapted to be engaged by the load block and a trip for said releasable connection actuated by said stop lever when the latter is shifted by the load block, said releasable connection being automatically reset upon return of said manually controlled means tothe position which it normally occupies when the switch is in open position.v

. drum, said gear set having one ring gear constrained to a limited amount of rotary movement, a gearcasing enclosing saidj gear set,

6 93,053,055v and an automatic load brake for said hoisting camming means between said last-named disgdrum, also mounted insaid gear casing and comaxially to apply said brake,- and arms carried prising a braking disc, a one-way clutch between by said ring gear. and engagebfe with said lastsaid braking disc and said gear set, a xed braknamed disc for moving the same to cause the 5` ing disc engageable with one face of said rstcams to engage and shift said last-named disc v5 named discLan axially shiftable braking disc enaxially. gageable with the other face thereof, -cooperabie Y ROY J. WADD. l 

